IMPLICIT MODELLING OF GEOLOGICAL STRUCTURES: A CARTESIAN GRID METHOD HANDLING DISCONTINUITIES WITH GHOST POINTS
Price
Free (open access)
Transaction
Volume
122
Pages
11
Page Range
189 - 199
Published
2019
Paper DOI
10.2495/BE410171
Copyright
WIT Press
Author(s)
JULIEN RENAUDEAU, MODESTE IRAKARAMA, GAUTIER LAURENT, FRANTZ MAERTEN, GUILLAUM CAUMON
Abstract
In geology, implicit structural modelling constructs the geometry of geological structures (e.g. layers) by interpolating between sparse field data. A model is represented by a volumetric scalar field which is discontinuous on structural discontinuities such as faults or stratigraphic unconformities. The management of such discontinuities may involve boolean operations on several scalar fields or the creation of conformal meshes. Instead, we propose a ghost cell technique for the cartesian grid together with a set of relations between the ghost points, the regular nodes, and the discontinuities. Consequently, poor quality meshes are avoided and only the resolution of the grid has an impact on the solution. The modelling problem is posed as a least square’s minimization of a bending energy penalization on data mismatch functions and approximated by finite difference. As all relationships in the grid are implicitly defined, except close to the discontinuities, this algorithm is computationally efficient. We provide some benchmarks of the method on two-dimensional examples with folds, faults, and erosions.
Keywords
2D structural modelling, mesh reduction methods, energy penalization, ghost points